Nasa's Mars Rover Spirit has looked back at its landing pad and taken a stunning colour picture of the platform where it started its Martian adventure.

Colours in the image have been adjusted but scientists have not yet determined the "true" colour of the Martian rocks.

The rover will now pause by the rock Adirondack as it prepares to use a grinder to examine the rock's interior.

Spirit will be on the Red Planet for at least 90 Martian days to investigate whether Mars had a watery past.

Nasa scientists have used the colour calibration target, also known as the sundial, to adjust the image so that its hue is a close approximation of the colour of the Martian surface.

'True colours'

However, mission scientists will have to perform further calculations before they can produce an image that shows Mars' "true" colour.

In a statement read out at the press conference by a colleague, lead panoramic camera scientist Dr Jim Bell said: "This image conveys the wonder, excitement, pride and honour that goes along with this wonderful mission and the hardware that got us to Mars."

Nasa's logo has turned from blue to red

"It's a fantastic image," added mission engineer Randel Lindemann.

However, the image shows signs of the correction process to get the colour of the Martian surface as close as possible to its true colour.

The normally blue starscape - or "meatball" - that forms the Nasa logo has turned a muddy red. And blue insulating foam surrounding cables on the lander has turned bright pink.

The rover's panoramic camera took the image looking in an east-north-east direction. It is a composite picture that is four original images wide and three original images tall.

Rainy day

Meanwhile, analysis of data from the rover has been delayed due to a storm in Australia that has disrupted communications between Earth and the rover on Mars.

Ground controllers sent a package of data to Mars overnight. This package was transmitted by a radio telescope in Canberra, Australia, because this dish happened to be pointing towards Mars when the rover "woke up" on Wednesday.

The local thunderstorm interfered with this communication and the rover only received a weak signal from Earth.

"As a result, it didn't get all the data we wanted it to get," said mission manager Jennifer Trosper.

This delayed the rover's science activities for the day. It was to have started using its Rock Abrasion Tool (Rat) to grind into the rock Adirondack and take readings of its interior mineral make-up.

This will now either happen on Thursday or Friday GMT.

Spirit's twin rover Opportunity lands on the surface of Mars on 25 January GMT.

Mr Lindemann said the team had learned lessons from the way they retracted the airbags on Spirit's landing to ensure that Opportunity can depart its lander in a forward-facing direction.

Spirit had to pivot around 115 degrees on its lander because a "puffy" airbag blocked its path.